1. Field of the Invention
The present invention relates to valve devices for controlling the flow of intake air supplied to internal combustion engines, in particular, multicylinder internal combustion engines.
2. Description of the Related Art
In order to control the flow of intake air of multicylinder internal combustion engines, variable intake air systems having valve devices have been used. In particular, in order to shift nodes of acoustic oscillations the intake air may produce and to increase an effective intake-air column length, variable intake air systems known as “acoustic control induction systems (ACIS)” have been proposed.
Japanese Laid-Open Patent Publication No. 2000-55200 teaches a valve device for controlling the flow of intake air and for use with an acoustic control induction system. The valve device includes a valve body, a valve member, and an actuator. The valve body is made of resin and has a frame portion fittable into an opening defined within a partition wall. The partition wall is disposed within a tank chamber of a surge tank of an internal combustion engine in order to divide the tank chamber into sub-chambers. The valve member is rotatably mounted on the valve body in order to open and close an opening defined by the frame portion of the valve body. The valve member operates in order to permit and interrupt communication between the sub-chambers. The actuator serves to rotate the valve member.
In the above publication, a diaphragm-type, negative-pressure control device is typically incorporated as the actuator. However, this type of actuator involves various components and tubes, complicating assembly and increasing manufacturing costs.